The shell of a hearing instrument that resides in the ear must provide the internal volume necessary to house its various components while at the same time remain sufficiently small to fit in the user""s ear canal. Examples of these instruments are shown in U.S. Pat. Nos. 5,799,095; 5,889,874; 5,915,031; and 6,088,465, all incorporated by reference herein. Some of these components include a battery, a microphone, a receiver, the electronics, and packaging.